Due to the ever rising price of gasoline and the continued popularity of motor vehicles as a mode of transportation, much effort in the prior art has been directed to increasing the efficiency and/or gas mileage in motor vehicles. In addition, and often to the detriment of obtaining better gas mileage, further efforts in the prior art have been directed towards reducing the various pollutants emitted from motor vehicles. Needless to say, the prior art includes many different approaches to the problems of increasing the efficiency of internal combusion engines and for reducing the pollutants thereof.
Some of these prior art approaches are disclosed in the patented art. For example, in U.S. Pat. No. 4,177,779 (Ogle), a fuel economy system is disclosed in which the vacuum from an engine is used to draw gasoline vapors and air from the gasoline tank of the motor vehicle with the gasoline in the tank being heated by the engine coolant. Another prior art system, disclosed in U.S. Pat. No. 3,696,799 (Gauck), feeds gas vapors which normally escape from the gasoline tank to the carburetor to increase the gas mileage of the vehicle. In yet another system, disclosed in U.S. Pat. No. 3,630,698 (Baldwin), the vacuum of the engine is used to vaporize fuel located in a container, the vaporized fuel then being fed along with air to the combustion chamber.
In addition to the systems discussed above, a number of other systems have been devised for vaporizing gasoline. For example, the system disclosed in U.S. Pat. No. 4,191,153 (Strem et al) includes a supporting member to which the liquid gasoline is applied, the liquid gas being evaporated by air passing through this supporting member. A similar vaporizing system is disclosed in U.S. Pat. No. 4,197,820 (Trudel). In the latter system, gas vapors are picked up by ambient air passing through a splash assembly located in the fuel supply tank. Another common type of vaporization system uses air which is bubbled through the liquid gasoline. Typical of these systems are the devices disclosed in U.S. Pat. No. 4,011,847 (Fortino) and U.S. Pat. No. 474,838 (Lambert). A similar system in which air is bubbled through heated fuel is disclosed in U.S. Pat. No. 1,938,497 (Pogue). Vaporized fuel produced by air bubbling can also be used as a supplement to a carburetor as disclosed in U.S. Pat. No. 3,749,376 (Alm et al).
The prior art also provides for the use of heated combustion air to aid in the vaporization of gasoline. For example, in U.S. Pat. No. 4,083,343 (Paton), heated combustion air is added to the fuel/air mixture produced by the carburetor. In another prior art system, disclosed in U.S. Pat. No. 3,116,988 (Lauder), the atomized fuel and a small percentage of air are passed through a heating chamber where the fuel is vaporized. Next, unheated combustion air is added to the fuel/air mixture which is then introduced into the intake manifold of the internal combustion engine.
The foregoing patents represent only a relatively small number of the many attempts in the prior art to increase fuel efficiency and/or reduce pollutant emissions of internal combustion engines. However, the achievements of the prior art have obviously not been as great as desired and it is clear that the need for greater fuel efficiencies in internal combustion engines producing less pollutant emissons is still very much in existence and is one which is becoming increasingly critical.